System for imaging printing forms

ABSTRACT

A system for imaging printing forms includes a raster image processor breaking down a printing image data set into color separation data sets, a data storage medium for storing the color separation data sets generated by the raster image processor, the color separation data sets being printing location-nonspecific color separation data sets, and control devices and imaging devices. For the imaging of a printing form on the basis of one of the color separation data sets, each of the control devices drives one of the imaging devices to image the printing form in question. The system also includes a correction device integrated into each of the control devices to convert the printing location-nonspecific color separation data sets stored in the data storage medium into printing location-specific color separation data sets, which can be used to drive the imaging devices.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention pertains to a system for imaging printing forms with araster image processor for breaking down a printing image data set intocolor separation data sets, a storage medium for storing the colorseparation data sets, and control devices driving respective imagingdevices.

2. Description of the Related Art

When printing is carried out with rigid printing forms, a distinction ismade in principle between methods which work with write-once printingforms and those which work with rewritable printing forms. Printingmethods which use rewritable printing forms are referred to by thephrase “computer-to-press/direct imaging” printing methods.

Under the product name “DICOweb”, the applicant markets digital printingpresses, which work with rewritable and erasable printing forms. Whenprinting forms according to the DICOweb technology are used, a printingform carrier, i.e., a printing form cylinder, is subjected to an imagingstep. Imaging of the printing form may be followed by the fixing andconditioning of the imaged printing form. The basic principles of theDICOweb technology are known from Helmut Kipphan: Handbuch derPrintmedien [Printing Media Manual], Springer-Verlag, 2000, pp. 674-680.

An imaging unit is used to image a rewritable printing form, that is, toimage the printing form in question in an image data-oriented manner.According to the DiCOweb technology, an imaging device is used to applyimaging material by a thermal transfer process to the printing formcarrier. According to the prior art, a control device is used to controlthe imaging device by means of which a printing form can be imaged. Thiscontrol device is assigned to the imaging device and drives the imagingdevice in question on the basis of a color separation data set.

As done in practice, color separation data sets are obtained from aprinting image data set by a raster image processor. The colorseparation data sets provided by the raster image processor are thenconverted by a correction device into printing location-specific colorseparation data sets, which ultimately are stored in a data storagemedium. The printing location-specific color separation data sets storedin the data storage medium are made available to control devices, whereeach control device drives an imaging device to image a printing form.

In the systems known from practice for the imaging of printing forms,therefore, a raster image processor and a correction device are used togenerate printing location-specific color separation data sets. Theseprinting location-specific color separation data sets are then assignedto control devices, which drive imaging devices for imaging the printingforms. According to standard practice, therefore, the printinglocation-specific color separation data sets are provided sequentiallyin a central correction device.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a novel system forimaging printing forms.

The object of the present invention is met by a system for imagingprinting forms having a correction device integrated into each controldevice to convert the printing location-nonspecific color separationdata sets stored in the data storage medium into printinglocation-specific color separation data sets, which can be used to drivethe imaging devices.

In the inventive system for imaging printing forms, the printinglocation-specific color separation data sets are provided decentrally,where corresponding correction devices are integrated into the controldevices which serve to drive the imaging devices. In the inventivesystem for imaging printing forms, therefore, printinglocation-nonspecific color separation data sets are stored in the datastorage medium. The actual correction or adaptation of the printinglocation-nonspecific color separation data sets to the geometriccharacteristics of the printing press is not conducted until the dataarrive in the control devices. It is therefore done in a decentralizedand parallelized manner.

Other objects and features of the present invention will become apparentfrom the following detailed description considered in conjunction withthe accompanying drawings. It is to be understood, however, that thedrawings are designed solely for purposes of illustration and not as adefinition of the limits of the invention, for which reference should bemade to the appended claims. It should be further understood that thedrawings are not necessarily drawn to scale and that, unless otherwiseindicated, they are merely intended to conceptually illustrate thestructures and procedures described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

An exemplary embodiment of the invention is explained in greater detailbelow on the basis of the drawing, but the invention is not beconsidered limited to it:

FIG. 1 is a functional block diagram of a system for imaging printingforms according to the prior art; and

FIG. 2 is a functional block diagram of an inventive system for imagingprinting forms.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

The present invention pertains to a system for imaging printing forms.Before the inventive system for imaging printing forms is discussed, asystem for imaging printing forms according to the prior art will bedescribed on the basis of FIG. 1.

FIG. 1 thus shows a system for imaging printing forms as known from theprior art and including a raster image processor 10, which breaks down aprinting image data set into color separation data sets.

A color separation data set is generated for each color of inkparticipating in the printing process. If, thereafter, combined autotypeprinting is carried out with the use of the colors cyan, magenta,yellow, and black, the raster image processor 10 will provide four colorseparation data sets. The technique known from the prior art for imagingprinting forms also has a correction device 11, which generates,centrally and sequentially, printing location-specific color separationdata sets from the printing location-nonspecific color separation datasets provided by the raster image processor 10. The corrected, i.e.,printing location-specific, color separation data sets thus generatedare stored in a data storage medium 12. According to FIG. 1, fourcorrected, printing location-specific color separation data sets 13, 14,15, and 16 are stored in the data storage medium 12. Each of theprinting location-specific color separation data sets 13, 14, 15, and 16stored in the storage medium 12 is transmitted to a control device 17,which drives an imaging device 18 on the basis of the correspondingcolor separation data set. The imaging device 18 is used to applyimaging material to the printing form to be imaged for the colorseparation in question.

In contrast to the prior art system, FIG. 2 shows the structure of aninventive system for imaging printing plates. The inventive system forimaging printing plates has a raster image processor 20 which breaksdown a printing image data set into several color separation data sets.The number of color separation data sets provided by the raster imageprocessor 20 corresponds to the number of colors participating in theprinting process. The color separation data sets provided by the rasterimage processor 20 can be stored in the storage medium 21, where,according to FIG. 2, a total of four color separation data sets 22, 23,24, and 25 are stored in the storage medium 21. The number of colorseparation data sets depends, however, as previously mentioned, on thenumber of colors participating in the printing process.

The color separation data sets 22, 23, 24, and 25 which are stored inthe storage medium 21 of the inventive imaging system are uncorrectedand therefore printing location-nonspecific color separation data sets.

Each of the color separation data sets 23-25 stored in the storagemedium 21 can be sent to a control device 27, where a correction device27 a is integrated into each control device 27 to convert the printinglocation-nonspecific color separation data set into a printinglocation-specific color separation data set. This is then used by thecontrol device 27 in question to drive the corresponding imaging device28. The control devices 27 are therefore designed as control andcorrection devices.

A data storage medium 27 b can also be integrated into each of thecontrol devices 27 in addition to the correction device 27 a, so thatthe printing location-specific color separation data set generated bythe correction device 27 a integrated into the control device can bestored in the associated control device 27.

According to FIG. 2, the storage medium 21 is connected to the controldevices 27 by a multiplexer device 26. Each of the color separation datasets can be assigned selectively to a control device 27, and thus to animaging device 28, by the multiplexer device 26.

In the inventive system for imaging printing forms, therefore, printinglocation-nonspecific color separation data sets are corrected toprinting location-specific color separation data sets decentrally and inparallel in the control devices 27, which serve to drive the imagingdevices 28. That is, each of the color separation data sets for thedifferent colors of inks is corrected separately.

The color separation data sets are therefore printinglocation-nonspecific until they are corrected in the control devices 27,which means that a flexible assignment of the printinglocation-nonspecific color separation data sets to individual printinglocations is possible. Through the parallelization of the correction inthe control devices 27, a shorter throughput time can be realized. Inaddition, the correction performed to provide the printinglocation-specific color separation data sets becomes robust, because thecorrection in question is not conducted until just upstream of theactual printing location. Printing location-specific parameters such asscaling data and geometric data, which are used to correct the printinglocation-nonspecific color separation data sets and thus to provide theprinting location-specific color separation data sets, can be adapted inshort cycles, autonomously, in the printing location in question.

The printing location-nonspecific color separation data sets 22-25stored in the data storage medium 21 can also be made available to othersystems of a printing press such as a softproofing system 29 or a colordensity control device 30. Thus, the color separation data sets 22-25provided by the raster image processor 20 and stored in the data storagemedium 21 can be used multiple times.

Thus, while there have shown and described and pointed out fundamentalnovel features of the invention as applied to a preferred embodimentthereof, it will be understood that various omissions and substitutionsand changes in the form and details of the devices illustrated, and intheir operation, may be made by those skilled in the art withoutdeparting from the spirit of the invention. For example, it is expresslyintended that all combinations of those elements and/or method stepswhich perform substantially the same function in substantially the sameway to achieve the same results are within the scope of the invention.Moreover, it should be recognized that structures and/or elements and/ormethod steps shown and/or described in connection with any disclosedform or embodiment of the invention may be incorporated in any otherdisclosed or described or suggested form or embodiment as a generalmatter of design choice. It is the intention, therefore, to be limitedonly as indicated by the scope of the claims appended hereto.

1. A system for imaging printing forms, comprising: a raster imageprocessor breaking down a printing image data set into color separationdata sets; a data storage medium for storing the color separation datasets generated by the raster image processor, the color separation datasets being printing location-nonspecific color separation data sets;control devices and imaging devices, wherein, for the imaging of aprinting form on the basis of one of the color separation data sets,each of the control devices drives one of the imaging devices to imagethe printing form in question; and a correction device integrated intoeach of the control devices to convert the printing location-nonspecificcolor separation data sets stored in the data storage medium intoprinting location-specific color separation data sets, which can be usedto drive the imaging devices.
 2. The system of claim 1, wherein each ofthe control devices also includes a data storage medium so that theprinting location-specific color separation data set generated by thecorrection device can be stored in the each of the control devices. 3.The system of claim 1, further comprising a multiplexer device installedbetween the data storage medium and the control devices to assign theprinting location-nonspecific color separation data sets selectively tothe control devices.
 4. The system of claim 1 the printinglocation-nonspecific color separation data sets stored in the datastorage medium is available to other systems of a printing press.
 5. Thesystem of claim 4, wherein the printing location-nonspecific colorseparation data sets stored in the data storage medium is made availableto a softproofing system.
 6. The system of claim 4, wherein the printinglocation-nonspecific color separation data sets stored in the datastorage medium are available to a color density control device.